A wide range of polyesters with varying properties are commercially available. It can also be advantageous to blend polyesters together in order to develop new materials that take advantage of the properties of the specific components used in the blend. One example is using a PETG copolyester (which contains terephthalic acid (TPA), EG, and CHDM) in blends to improve properties such as lowering viscosity for extrusion processing, increasing adhesion for lamination processing, and altering the heat distortion temperature. Unfortunately, the PETG copolyester is generally not miscible with some other copolyesters such as a PCTT copolyester (which contains TPA, CHDM, and TMCD). Because they are generally immiscible and have different refractive indices, blends of PETG and PCTT typically exhibit an unacceptable level of haze in an extruded film.
Thus, there is a need in the art for polyester blends containing PETG and PCTT that exhibit an acceptable level of haze.
The present invention addresses this need in the art as well as others that will become apparent from the following description and the appended claims.